At the recent K 2016, ExxonMobil introduced its new low-viscosity performance additive of the Vistamaxx™ series. This resin can serve for maintaining/improving cycle times in extrusion and injection molding alike. Particularly, Vistamaxx 8880 improves flow and processing of polyolefin compounds with Vistamaxx 6202 or 6502 in their formulations.
Gertrud Masure, market development manager for Vistamaxx at ExxonMobil Chemical, explains: “Vistamaxx polymers are used for compound modification at dosage levels of 5 to 15% in order to enhance properties such as impact strength and clarity, while reducing stress whitening. For applications such as grips, however, dosage levels have to be much higher to achieve the required performance improvements which can result in longer cycle times.”
The premiered low-viscosity Vistamaxx 8880 helps in overcoming this by reducing cycle times to an adequate level. “Compounders can now tailor processing and product performance even more by using Vistamaxx 8880 to modify viscosity. They can achieve product improvements by including Vistamaxx 6202 and 6502 in their formulations, while processing performance is maintained or enhanced by using Vistamaxx 8880 in the same formulations,” adds Masure.
Inclusion of Vistamaxx 8880 in a formulation moderates injection pressure thanks to its low viscosity and cooling efficiency, thus improving the entire process. Cooling temperature control makes it possible to achieve cycle times equivalent to these for SEBS (styrene-ethylene-butylene-styrene) compounds used for soft-touch TPE applications such as overmolding and grips.
By reducing formulation viscosity, Vistamaxx 8880 enhances its blending properties, which results in higher flexibility and impact resistance, as well as in improved product appearance.
A better processing with Vistamaxx 8880 means cutting down unit cost, all the way from compounding to extrusion or injection molding. Enhanced flowability enables increased production rates and overall cost performance for processors, with Vistamaxx 6202/6502 still reducing material costs by allowing for higher filler loadings.
When it comes to end users, they enjoy better products such as stay-flat carpet tiles or non-slippery TPE grips. In carpet tiles, secondary support layer may be made of a highly filled polyolefin compound that provides for flexibility while keeping the required nondeformity. Costs are cut down here thanks to higher filler loadings (by adding Vistamaxx 8880 to a Vistamaxx 6202/6502-based material), scrap recycled in the process, and lower compound density. The latter also results in higher flowability, enhancing compound processability during extrusion.
As for TPE grips, oil-free Vistamaxx 6202/6502 provide for soft non-slippery feel due to improved surface quality of products. Stress whitening can also be minimized, and overall costs reduced by up to 20% due to filler loadings of up to 30% made possible. Finally, addition of Vistamaxx 8880 in the formulation keeps cycle durations equivalent and flow higher with the same machine and tooling.
“Vistamaxx 8880 is symbolic of the possibilities that the Vistamaxx polymer portfolio can deliver. It allows application or process innovation to be tailored to the benefit of compounders, brand owners and end-users,” sums it up Masure.
